Projects
simultaneously requiring 25±2°C and 95±5% RH. Ventilation
needs involved adhering not only to regulatory fresh air and
fire rational requirements, but also ensuring that test-specific
ventilation needs are met. These included fume cupboard
ventilation, negative pressure spaces, positive pressure spaces,
dedicated toxic gas ventilation, and dust filtration.
In addition to HVAC and building management systems
(BMS) services, the spaces also required a plethora of other
building services such as a compressed air network, various
laboratory gas supplies, a hydraulic network to heavy
machinery, as well as electrical and wet services to the
various laboratory equipment and services. Furthermore, the
architectural design intent involved mostly exposed services to
align with the educational purposes of the facility. The design
challenge was therefore to ensure the individual laboratory
needs are met, whilst also providing the most sustainable
design possible, all within the context of a service-intensive
and aesthetically sensitive building.
Humidity room typical air handling units.
Ventilation in curing bathrooms.
HVAC SYSTEM
The HVAC system at UP Engineering 4.0 involves a central
air-cooled chilled and hot water generation plant as cooling
and heating source, located at ground level. Chilled water at
8°C and hot water at 50°C is circulated via a 4-pipe closedloop
piping system to a network of air handling units and fan
coil units. The pumping arrangement includes a decoupled
primary-secondary loop with hot and cold buffer tanks and
variable volume secondary pumps to ensure pumping power
is minimised whenever possible, in line with the cubic flowpower
affinity law. Using a 4-pipe system reduced the baseline
HVAC electrical energy usage by 68% with an estimated
payback period of 3.9 years. Furthermore, no water consuming
heat rejection systems were used, and all refrigerants were
specified with an Ozone Depletion Potential (ODP) of zero.
The SANRAL laboratories are served by a series of aboveceiling
chilled water fan coil units and various ventilation
systems. A dedicated fresh air unit provides filtered,
tempered and pre-conditioned fresh air to all spaces. A
general central extraction system ensures neutral pressure
in general laboratories. An independent bitumen extraction
system ventilates from canopies and grilles located over
oven areas where bitumen fumes are generated and ensures
negative pressure in these spaces to avoid smell and fume
contamination. Seven different fume cupboards ensure that
tests involving toxic gasses such as Toluene can be carried
out safely.
These fume cupboards are connected to two dedicated
extraction systems using centrifugal fans and above-roof
level exhausts. Each fume cupboard extraction system is
also interlocked with a dedicated fresh air make-up system
32
RACA Journal I August 2020
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